1. Field of the Invention
The present invention relates to a fermentation process for the production of pradimicin antibiotics, and to the producing microorganism of said antibiotics. 2. Background Art
Among the various reported members of the pradimicin family produced by Actinomadura, pradimicins FA-1 (Ia) and FA-2 (Ib), disclosed in U.S. Pat. No. 4,973,673, contain a D-serine moiety. Benanomicin A (II), a compound closely related to the pradimicins, has been reported in J. Antibiot., 1988, 41:807-811; it differs from the pradimicins in lacking the sugar amino group of the pradimicins. European Patent Application 432,527 published Jun. 19, 1991 discloses the compound 4'-deamino-4'-axial-hydroxypradimicin FA-2 (III, hereinafter referred to as BMY-28960) which was prepared from pradimicin FA-2 by chemical means. Desxylosyl BMY-28960 is also generically disclosed in EP 432,527 and may be prepared from desxylosyl pradimicin FA-2. ##STR1##
The chemical processes for preparing BMY-28960 and its desxylosyl derivative are difficult and laborious, and produce the products in low yield. Thus, an alternative process suitable for mass production of these antibiotics is highly desirable. As a result of an intensive search for microorganisms capable of producing BMY-28960 and desxylosyl BMY-28960, a novel microorganism strain belonging to the genus Actinomadura was found to be such an antibiotic producer.